1. Field of the Invention
The present invention relates to a small watercraft, and more particularly to a hull design for a small watercraft.
2. Description of Related Art
Personal watercraft have become very popular in recent years. This type of watercraft is quite sporting in nature and carries a rider and possibly one, two, three or four passengers. A relatively small hull of the personal watercraft commonly defines a riders' area above an engine compartment. An internal combustion engine frequently powers a jet propulsion unit which propels the watercraft. The engine lies within the engine compartment in front of a tunnel formed on the underside of the watercraft hull. The jet propulsion unit is located within the tunnel and is driven by the engine.
Power demands on personal watercraft engines have increased in recent years with the increased number of passengers and loads the watercraft are designed to carry, with a desire for faster top-end speeds, and with towing requirements. Larger size engines thus typically power personal watercraft these days to meet these demands. For instance, most watercraft manufacturers now provide three-cylinder engines with their larger watercraft models (i.e., three- and four-seaters). Larger engines though are heavier.
The increased weight of the engine, and thus the watercraft, causes the watercraft to float at a lower position in the water. This lower position (i.e. greater hull displacement) increases the time required to accelerate the watercraft from rest to planing speeds. While the larger engine improves the watercraft's performance some of the performance gains are lost because the watercraft hull starts from a deeper position and cannot pop-up on plane as quickly.
Larger engines also pose design problem because personal watercraft usually have relatively small engine compartments. In order to handle increased intake air and exhaust gas volumes, the associated induction and exhaust systems of the engine desirably increase in size, which exacerbates the problems associated with the compact size of the engine compartment. The induction and exhaust systems consequently are forced to assume sharply curved flow paths (i.e., flow paths including bends having small radii of curvature). Such tight bends in the flow path of intake and exhaust gases reduces engine performance. For instance, such tight bends in the exhaust system increase the back pressure in the exhaust system, which interferes with the proper exhaustion of the burnt charges from the combustion chambers of the engine cylinders.
A need therefore exists for an improved hull design that improves the buoyancy of the watercraft and provides increased room within the hull to accommodate larger engines.